The invention relates generally to planting implements and, more specifically, to a clutch that controls the operation of a seed meter on a planting implement to reduce planter overlap.
In many parts of the world row crops must be planted in a short timeframe to achieve maximum yield. Farmers seeking to expand their cropland must do it without expanding the duration of planting beyond the optimum time period. Because farmers find it more efficient to use a wider planter instead of adding another planter and operator, planter manufacturers have expanded row crop planter widths. However, one undesired condition that gets worse as planter width increases is overlap.
Overlap occurs each time planter passes intersect (FIG. 1). Wider planters produce greater overlap because all rows are planting whenever the planter is moving and row units are engaged with the soil. Farmers experience economic loss in overlap areas because seed is wasted and yield is reduced compared to non-overlap areas. Essentially overlap areas are planted twice or more depending on the number of intersecting passes. Extra plants in overlap areas take soil nutrients and moisture from the intended plants, which results in reduced yield compared to non-overlap areas. Farmers contend with these conditions at end rows, point rows and waterways.
Electric actuated drill shaft clutches are recognized as the first device to reduce overlap on row crop planters. These clutches turn groups or sections of seeding units (called rows) on and off. The planter operator manually turns these clutches on and off when the planter section intersects another pass.
Electric drill shaft clutches turn rows on and off by controlling a section of the drill shaft. The drill shaft spans across the planter toolbar and rotates at a speed proportional to the speed of the planter. Row units, each containing a seed meter device, are attached to the planter toolbar. Each row's seed meter is mechanically connected (commonly with a chain) to the drill shaft. Each drill shaft section turns a bank of rows on and off at the same time. The electric clutch turns seeding on and off by mechanically engaging and disengaging the drill shaft section to the planter transmission. Smaller width planters are typically made with one drill shaft section. Larger width planters are commonly made with two to four drill shaft sections to allow for planter folding. Each drill shaft section is fitted with a drill shaft clutch.
Other prior art is a pneumatic actuated sprocket clutch that controls each row independently, such as those described in published U.S. patent applications 2007/0151,492 and 2007/0151,824. Pneumatic actuated clutches are electrically controlled by an electric over air valve. The drill shaft must be removed for sprocket clutch installation, repair or replacement.
Electrical current requirements of the electric over air valve are much less compared to an electric drill shaft clutch. Another advantage of sprocket clutches over drill shaft clutches is that the planter can be subdivided into more sections without creating more drill shaft sections. This is beneficial for retrofit installations.
Another prior art is a pneumatic actuated clutch mounted outside the row unit at the seed meter input shaft. The advantage of this over the sprocket clutch is installation doesn't require removal of the drill shaft. A big disadvantage is that the clutch is exposed to flying debris from planter lift wheels.
Initially the planter operator manually turned all the aforementioned clutches or planter sections on and off manually. In practice, most operators find it difficult to do this accurately because the planter is moving and they need to observe other machine functions. More planter sections make the task more difficult.